South Carolina tomatoes (not implicated in the outbreak). Credit: Donna DeMichael originally published on sc.gov

SUNDAY June 29, 2008 (foodconsumer.org) -- The United States Centers for Disease Control and Prevention (CDC) updated the ongoing Salmonella outbreak on June 27 saying that since April, 810 cases of salmonella in 36 states and the District of Columbia had been confirmed based on genetic fingerprinting to be caused by the same strain.

The CDC said consumption of raw tomatoes had been identified as the likely source of the illnesses while the specific type and source of tomatoes is under investigation.

The agency also said that data suggest that illnesses were linked to consumption of raw red plum, red Roma, or round red tomatoes or any combination of these types of tomatoes and to products containing these raw tomatoes.

Officials at the Food and Drug Administration said Friday that it might be impossible to trace the source of the outbreak because the industry commonly mixes tomatoes from different farms at produce distribution centers and then sell them, Los Angeles Times reports.

Dr. David Acheson, an associated commissioner for the FDA said, cited by the times as saying that possibly 90 percent of tomatoes might be repacked, making it virtually impossible to trace the source.

The FDA investigation into the multistate salmonella outbreak began on May 31 when the CDC notified FDA of the possible link between the outbreak and consumption of raw red Roma, plum, and round tomatoes, according to a document released by the FDA on June 27.

The FDA said it was inspecting and investigating farms and other critical points on the supply chain where the tomatoes may have become contaminated.